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New Polyether Toxins From Shellfish And Marine Phytoplankton: Isolation Studies And Development Of Analytical Methods, Alan G. Bishop

Theses

There are three classes of polyether toxins responsible for Diarrhetic Shellfish Poisoning (DSP) world-wide. The causative toxins are okadaic acid (OA) and derivatives (DTXs), pectenotoxins (PTXs) and yessotoxins (YTXs). The origin of these toxins are phytoplankton from Dinophysis or Prorocentrum spp. OA has been demonstrated for most outbreaks in Europe and more recently a new isomer DTX-2 has been reported in Ireland.

Marine phytoplankton biomass samples consisting predominantly of Dinophysis acuta, were acquired using a large double plankton net from waters off the South-west coast of Ireland. Analysis of unialgal samples using high performance liquid chromatography (HPLC) with fluorescence and …

Resource Allocation And Sucrose Mobilization In Light Limited Eelgrass Zostera Marina, Teresa Alcoverro, Richard C. Zimmerman, Donald G. Kohrs, Randall S. Alberte

OES Faculty Publications

This study evaluated the ability of Zostera marina L. (eelgrass) to balance the daily photosynthetic deficit by mobilization of carbon reserves stored in below-ground tissues during a period of extreme winter light limitation. A quantitative understanding of the mobilization process and its limitations is essential to the development of robust models predicting minimum light levels required to maintain healthy seagrass populations. Plants were grown in running seawater tanks under 2 light regimes. One treatment was provided with 2 h irradiance-saturated photosynthesis (H_sat) to produce severe Light Limitation, while control plants were grown under 7 h H_sat, …

Comparative Study Of Selenium Requirements Of Three Phytoplankton Species: Gymnodinium Catenatum, Alexandrium Minutum (Dinophyta) And Chaetoceros Cf. Tenuissimus (Bacillariophyta, Martina A. Doblin, Susan I. Blackburn, Gustaaf M. Hallegraeff

OES Faculty Publications

This study investigated the selenium (Se) requirements of three phytoplankton species which commonly bloom in southern Australian estuaries. The present study showed that the toxic dinoflagellate Gymnodinium catenatum Graham had an obligate requirement for Se (IV) in culture. After two transfers (~ 4 weeks ≈ 7 generations) in Se-deficient seawater medium, this phytoplankton species exhibited a decline in growth rate (25%) and biomass yield (90%), while complete cessation of cell division occurred under prolonged (8 weeks ≈ 12 generations) Se starvation. Addition of 10^-9-10^-7 M H₂SeO₃ to nutrient-enriched seawater medium resulted in increased G.catenatum …

Effects Of Diflubenzeron On The Ontogeny Of Phototaxis By Palaemonetes Pugio, J.E.H. Wilson, R.B. Forward Jr., J.D. Costlow

Gulf and Caribbean Research

The phototaxis by larvae of the grass shrimp Palaemonetes pugio that hatched from embryos which were exposed to a single pulse concentration of diflubenzuron (DFB; Dimilin®) was quantified. Stage IV embryos (6-day-old) were exposed to 0.5 µg/L of DFB for 4 days followed by transfer into clean seawater for the rest of the incubation period. The photoresponses of light-adapted larvae from untreated embryos and embryos treated with 0.5 µg/L DFB were monitored from 1 day through 8 day post hatch for phototactic responses to 500 nm light. Larvae from untreated embryos exhibited strong positive phototaxis at high light intensities (3 …

Modeling The Msx Parasite In Eastern Oyster (Crassostrea Virginica) Populations. Iii. Regional Application And The Problem Of Transmission, Eric N. Powell, John M. Klinck, Susan E. Ford, Eileen E. Hofmann, Stephen J. Jordon

CCPO Publications

A model of transmission for Haplosporidium nelsoni, the disease agent for MSX disease, is developed and applied to sites in Delaware Bay and Chesapeake Bay. The environmental factors that force the oyster population- H. nelsoni model are salinity, temperature, food, and total suspended solids. The simulated development of MSX disease was verified using 3 time series of disease prevalence and intensity: 1960 to 1970 and 1980 to 1990 for Delaware Bay, and 1980 to 1994 for Chesapeake Bay, and for a series of sites covering the salinity gradient in each bay. Additional simulations consider the implications of assumptions made …

Modeling The Msx Parasite In Eastern Oyster (Crassostrea Virginica) Populations. Ii. Salinity Effects, Michelle C. Paraso, Susan E. Ford, Eric N. Powell, Eileen E. Hofmann, John M. Klinck

CCPO Publications

An oyster population model coupled with a model for Haplosporidium nelsoni, the causative agent of the oyster disease MSX, was used with salinity time-series constructed from Delaware River flow measurements to study environmentally-induced variations in the annual cycle of this disease in Delaware Bay oyster populations. Model simulations for the lower Bay (high salinity) sire reproduced the annual cycle observed in lower Delaware Bay. Simulations at both upper Bay (low salinity) and lower Bay sites produced prevalences and intensities that were consistent with field observations. At all sites, low freshwater discharge resulted in increased disease levels, whereas high freshwater …

Modeling The Msx Parasite In Eastern Oyster (Crassostrea Virginica) Populations. I. Model Development, Implementation, And Verification, Susan Ford, Eric Powell, John Klinck, Eileen Hofmann

CCPO Publications

A mathematical model simulating the host-parasite-environmental interactions of eastern oysters (Crassostrea virginica) and the pathogen, Haplosporidium nelsoni, which causes MSX disease, has been developed. The model has 2 components. One replicates the infection process within the oyster and the other simulates transmission. The infection-development component relies on basic physiological processes of both host and parasite, modified by the environment, to reproduce the observed annual prevalence cycle of H. nelsoni. Equations describing these rates were constructed using data from long-term field observations, and field and laboratory experiments. In the model, salinity and temperature have direct effects upon …

Growth And Feeding Studies On The Algal Feeding Stage Of A Pfiesteria-Like Dinoflagellate, David W. Seaborn, A. Michelle Seaborn, William M. Dunstan, Harold G. Marshall

Virginia Journal of Science

The dinoflagellate Cryptoperidiniopsis sp. was isolated from sediment samples taken from Virginia estuaries, and established in culture for subsequent growth and feeding studies. The maximum abundance, or yield, of Cryptoperidiniopsis is exponentially related to the concentration of algal prey and is saturated at about 4.00 X 10⁵ mL^-1. Salinity from 10-20 ppt and temperature between 15-25 C have no effect on the yield of this form of Cryptoperidiniopsis. Light intensity has a secondary effect in that the algal prey reproduces more quickly in higher light as they are being grazed. Growth rates of Cryptoperidiniopsis were …

Water Quality Relationships To Concentrations Of Pfiesteria-Like Organisms In Virginia Estuaries For 1998, Everett P. Weber, Harold G. Marshall

Virginia Journal of Science

A series of statistical analyses were performed to identify the relationship between abundance of dinoflagellates grouped as Pfiesteria-like organisms and a set of 25 water quality variables from May through October of 1998 at 41 estuarine locations. Although regions were identified in relation to seasonal density of cells present, there were no strong relationships to specific water quality variables. Factors that may have influenced these results included: a) several species were included in the group analyzed and this composite did not respond as a unit to changing environmental conditions; b) cell concentrations were low and there were a large …

Modeling The Effects Of Doliolids On The Plankton Community Structure Of The Southeastern Us Continental Shelf, A. G. Edward Haskell, Eileen E. Hofmann, Gustav-Adolf Paffenhofer, Peter G. Verity

CCPO Publications

A model of the lower trophic levels that consists of a system of coupled ordinary differential equations was developed to investigate the time-dependent behavior of doliolid populations associated with upwelling features on the outer southeastern US continental shelf. Model equations describe the interactions of doliolids with two phytoplankton size fractions, five copepod developmental stages and a detrital pool. Additional equations describe nitrate and ammonia. Model dynamics are based primarily upon data obtained from field and laboratory experiments for southeastern US continental shelf plankton populations. Variations on a reference simulation, which represents average upwelling conditions without doliolids, were carried out to …

The Whales Have Not Been Saved, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

The Blind Cave Fish That Never Was, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

A Survey Of The Reef-Related Medusa (Cnidaria) Community In The Western Caribbean Sea, E. Suarez-Morales, L. Segura-Puertas, R. Gasca

Gulf and Caribbean Research

The species composition, distribution, and abundance of medusae collected during a 4-day plankton survey in a reef system of the Mexican Caribbean were studied. Highest mean medusae abundance was observed over the fore-reef zone and in daytime samples. Lowest abundances occurred in the reef lagoon and at dusk. Seventeen species were identified, with Liriope tetraphylla, Aglaura hemistoma, Cubaia aphrodite, and Sarsia prolifera being the most abundant. They belong to a group of medusae dominant along the world's second largest barrier reef. Cluster analysis revealed primary (fore-reef) and secondary (reef lagoon, channel) oceanic groups, showing the strong oceanic …

An Annotated Checklist And Key To Hermit Crabs Of Tampa Bay, Florida, And Surrounding Waters, Karen M. Strasser, W. Wayne Price

Gulf and Caribbean Research

Fourteen species of hermit crabs, belonging to 5 genera, were identified from 35 stations in Tampa Bay and adjacent continental shelf waters. Ninety-two samples were taken from the intertidal zone to 15 m with a variety of gear including dip nets, trawls, dredges, and hand collections using SCUBA. Pagurus maclaughlinae, Pagurus longicarpus, and Pagurus pollicaris were distributed throughout the bay. These species were often sympatric, and were commonly found in seagrass beds, sandy substrates, and sand/mud substrates, respectively. Clibanarius vittatus, Pagurus gymnodactylus, and Pagurus stimpsoni inhabited the higher salinity waters of the bay entrance. Paguristes sp., …

The Planktonic Copepods Of Coastal Saline Ponds Of The Cayman Islands With Special Reference To The Occurrence Of Mesocyclops Ogunnus Onabamiro, An Apparently Introduced Afro-Asian Cyclopoid, Eduardo Suarez-Morales, Jerry A. Mclelland, Janet Reid

Gulf and Caribbean Research

Taxonomic analysis of the copepod specimens collected from 29 Cayman Island ponds revealed the presence of ten species including the nearly ubiquitous cyclopoid Apocyclops panamensis. This species was widespread throughout the islands, being collected at 27 of the sampling sites. Another common calanoid, Mastigodiaptomus nesus, occurred at nine sites on Grand Cayman and one on Cayman Brac. A cyclopoid of Afro-Asian origin, Mesocyclops ogunnus, was collected at two nearly fresh water sites on Grand Cayman and was considered to be a recent introduction. Because of its known adaptability to fluctuating environmental conditions, it is likely that M. …

Gulf Estuarine Research Society Spring 1999 Meeting Abstracts

Gulf and Caribbean Research

Meeting abstracts from the Spring 1999 meeting of the Gulf Estuarine Research Society.

Atlas Of Fishes Of The St. Louis Bay Drainage In Southern Mississippi, Royal D. Suttkus, David A. White, Maurice F. Mettee

Gulf and Caribbean Research

This atlas presents a comprehensive report on fishes collected in the St. Louis Bay drainage between October 1950 and October 1989, prior to several recent years of accelerated commercial and residential development. A total of 261 samples taken at 126 sites from headwaters of major streams to the mouth of St. Louis Bay resulted in the collection of 75,625 specimens representing 124 species plus 2 hybrid sunfish combinations. Precise locality data are given for each collection site, with number of species and specimens taken at each site, followed by a total list of species taken at each site. A distribution …

The Cause And Consequence Of Ontogenetic Changes In Social Aggregation In New Zealand Spiny Lobsters, Mark J. Butler Iv, Alistair B. Macdiarmid, John D. Booth

Biological Sciences Faculty Publications

Ontogenetic changes in the behavior, spatial distribution, or habitat use of a species are presumably adaptations to ecological forces that differ in their effect on various life stages. The New Zealand rock lobster Jasus edwardsii is one of several species of spiny lobster that exhibits dramatic ontogenetic shifts in sociality and spatial distribution, and we tested whether such changes are adaptive. We first surveyed several natural populations of J. edwardsii to document size-specific differences in aggregation. To determine if chemical cues discharged by conspecifics promote aggregation of certain ontogenetic stages, we tested the responsiveness of lobsters of 3 ontogenetic stages …

Growth And Feeding Studies On The Algal Feeding Stage Of A Pfiesteria-Like Dinoflagellate, David W. Seaborn, A. Michelle Seaborn, William M. Dunstan, Harold G. Marshall

Biological Sciences Faculty Publications

The dinoflagellate Cryptoperidiniopsis sp. was isolated from sediment samples taken from Virginia estuaries, and established in culture for subsequent growth and feeding studies. The maximum abundance, or yield, of Cryptoperidiniopsis is exponentially related to the concentration of algal prey and is saturated at about 4.00 X 10⁵ mL^-1. Salinity from 10-20 ppt and temperature between 15-25 C have no effect on the yield of this form of Cryptoperidiniopsis. Light intensity has a secondary effect in that the algal prey reproduces more quickly in higher light as they are being grazed. Growth rates of Cryptoperidiniopsis were …

Department Of Fisheries Annual Report 1998/99, Department Of Fisheries, Western Australia

Department of Fisheries Annual Reports

In accordance with Section 62 of the Financial Administration and Audit Act 1985, I submit for your information and presentation to Parliament the Annual Report of the Fisheries Department for the financial year ending 30 June 1999.

The Annual Report of Fisheries WA has been prepared in accordance with the provisions of the Financial and Administration and Audit Act 1985 and Secon 263 of the Fish Resouces Management Act 1994.

Recent Trends In Water Clarity Of Lake Pontchartrain, J.C. Francis, M.A. Poirrier

Gulf and Caribbean Research

An analysis of Secchi disk transparency observations from 3 sites on the Lake Pontchartrain Causeway indicates that water clarity has increased at the north shore and mid-lake sites, but has not changed at the south shore site. Louisiana Department of Environmental Quality data from 1986 through 1995 were used in the analysis. Further analysis indicates that the increased transparency was not caused by changes in salinity or wind speed. The best explanation for the observed increase is the cessation of shell dredging in 1990.

Parasitization Of Callinectes Rathbunae And Callinectes Sapidus By The Rhizocephalan Barnacle Loxothylacus Texanus In Alvarado Lagoon, Veracruz, Mexico, Fernando Alvarez, Adolfo Gracia, Rafael Robles, Jorge Calderon

Gulf and Caribbean Research

Callinectes rathbunae and CalIinectes sapidus in Alvarado Lagoon, Mexico, were sampled monthly for one year to determine the extent of parasitization by the rhizocephalan cirripede Loxothylacus texanus. Prevalence levels. host sex ratio, carapace width-weight variation, and distribution of the number of parasites among hosts were analyzed. Loxothylacus texanus was present almost exclusively in C. rathbunae with a mean prevalence of 7.58%, while less than 1% of all C. sapidus were parasitized. Callinectes rathbunae constitutes a new host record for this parasite. A study of infection revealed significant variation in prevalence and host size throughout the study period. The sex …

Analysis Of Increases In Fishing Power In The Western Rock Lobster (Panulirus Cygnus) Fishery, John Fernandez

Theses: Doctorates and Masters

The western rock lobster, Panulirus cygnus, fishery represents a significant commercial asset to Western Australia, and it is therefore important that appropriate strategies are developed to effectively manage it. Because the fishery has a very high level of exploitation, researchers and managers rely significantly on annual stock assessments which are based on catch and effort data. This study will identify and assess the effects that changes in fishing power factors (e.g. advances in fish-finding technology) have had on estimates of catch and effort. The fishing power increases can be used to adjust nominal fishing effort to produce a time series …

Variations In The Ventral Ciliature Of The Crustacean Symbiont Hyalophysa (Ciliophora, Apostomatida) From Mobile Bay And Dauphin Island, Alabama, Stephen C. Landers, Michael A. Zimlich, Tom Coate

Gulf and Caribbean Research

Apostome ciliates are symbiotic organisms whose life cycles are complex and involve specific feeding, divisional, migratory, and phoretic stages. In this study we examined apostome trophonts (the diagnostic stage) from a variety of crustacean hosts in the Mobile Bay and Dauphin Island, Alabama, area. The hosts were grass shrimp (Palaemonetes pugio and P. paludosus), striped hermit crab (Clibanarius vittatus), blue crab (Callinectes sapidus), and pink shrimp (Farfantepenaeus (=Penaeus) duorarum). A number of similar but distinct morphotypes of apostomes were present, those corresponding to descriptions of species of Hyalophysa as well …

Water Quality Relationships To Concentrations Of Pfiesteria-Like Organisms In Virginia Estuaries For 1998., Everett P. Weber, Harold G. Marshall

Biological Sciences Faculty Publications

A series of statistical analyses were performed to identify the relationship between abundance of dinoflagellates grouped as Pfiesteria-like organisms and a set of 25 water quality variables from May through October of 1998 at 41 estuarine locations. Although regions were identified in relation to seasonal density of cells present, there were no strong relationships to specific water quality variables. Factors that may have influenced these results included: a) several species were included in the group analyzed and this composite did not respond as a unit to changing environmental conditions; b) cell concentrations were low and there were a large …